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A modified turbulent heat-flux model for predicting heat transfer in separating-reattaching flows and film cooling applications

Mazaheri, K ; Sharif University of Technology | 2017

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  1. Type of Document: Article
  2. DOI: 10.1016/j.applthermaleng.2016.09.018
  3. Publisher: Elsevier Ltd , 2017
  4. Abstract:
  5. The present study addresses a new effort to improve the prediction of the thermal field in separating-reattaching flows by making modifications in a low-Reynolds-number (LRN) version of HOGGDH heat-flux model proposed by Suga and Abe (2000). The modifications are based on introducing non-equilibrium effects of hydrodynamic flow field in the heat-flux model. Using an analytical approach, we have implemented P/ε, ignored in the base version, to the modified version. To do so, the model structure was changed and a damping function which is more sensitive to non-equilibrium flow features is also applied to the model. The modified heat-flux formulation along with a second moment closure hydrodynamic model is validated in a backstep flow, a periodic ribbed duct flow and a 3D high-blowing-ratio film cooling flow. Promising results are obtained compared with GGDH and HOGGDH models and the model performance is found to be comparable to θ2¯-εθ heat models, but with less computational and implementational complexity. For the film cooling flow, the rapid cooling efficiency drop due to the jet lift-off is accurately predicted though some margins to be improved still remain. © 2016 Elsevier Ltd
  6. Keywords:
  7. Film cooling ; Heat-flux model ; Non-equilibrium flow ; Separating-reattaching flow ; Cooling ; Fighter aircraft ; Fluid dynamics ; Heat transfer ; Hydrodynamics ; Reynolds number ; Heat flux models ; Hydrodynamic flow fields ; Non-equilibrium effects ; Non-equilibrium flows ; Reattaching flows ; Second-moment closures ; Turbulent heat fluxes ; Heat flux
  8. Source: Applied Thermal Engineering ; Volume 110 , 2017 , Pages 1609-1623 ; 13594311 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/pii/S1359431116316155